An inhibiting factor in the use of fluid pressure-operated systems for automation and control purposes is the need for expertise in the design of the relevant circuits that must link perhaps a large number of operating components in an appropriate relationship to achieve the operation of the respective components in a specific order and/or timed relationship. In a system of any complexity a large number of interconnections are required and if these are to be effected by means of conventional piping and connectors the layout of such elements requires considerable skill, while the ultimate assembly of such elements equally involves skill and the utilisation of considerable space. The space requirements may impose major constraints upon the operational possibilities achievable witin a given envelope. Moreover, assembly faults may easily occur, and the tracing of such faults, and of component faults arising in operation, can be extremely difficult and time consuming.
In addition, a complex system having its components interconnected by conventional elements to achieve a given operational function and/or sequence cannot often be readily rearranged ("programmed") to achieve another operational function and/or sequence without major disassembly and redesign of the component interconnections.
For all these reasons the development and utilisation of fluid pressure-operated systems for control and like purposes has suffered undesirable constraints. An object of the present invention is to provide an interconnection unit to which a plurality of operational components of a fluid pressure-operated system may be connected and that allows the ready established of desired interconnections between such components and, likewise the simple rearrangement of such interconnections when required.